3pEA4. Speech intelligibility in Grady Gammage Memorial Auditorium.

Session: Wednesday Afternoon, June 18

Time: 2:40

``The most important function of sound in theater is to ensure audience
comfort in perceiving audio component of a performance'' [Bracewell, Sound
Design of Theater (1993)]. Background research has unveiled poor speech
intelligibility at the Gammage Auditorium. This study aims to map speech
intelligibility in different seating areas and measure the factors causing poor
speech intelligibility. The instrument used to collect data will be the Techron
TEF System 12 analyzer. This instrument uses modulation transfer function (MTF)
and speech transmission index (STI) techniques. This is based on RASTI
techniques by measuring the reduction of signal modulation in an acoustic
transmission path [Keele, Jr. (1988)]. MTF is a measure of how well the
amplitude modulation of a signal is preserved when a signal is sent from one
point to another. The measurement modulations at different frequencies are
converted to a single value that indicates the speech intelligibility in the
auditorium. This single value is STI. Measurements are also provided on data for
signal-to-noise ratio and RT[inf 60]. A separate measurement of background noise
level would indicate poor speech intelligibility due to excessive reverberation
or background noise.